1. Field of the Invention
This invention relates to downhole tools in an oil well. More particularly, the invention relates to a method and apparatus for positively verifying complete deployment of a downhole tool.
2. Prior Art
Conventionally, information regarding the extent to which inflatable elements had been inflated by an actuation hereof was limited to pressuring up in the downhole environment either above or below the inflatable element in determining whether such pressure would be maintained. While in a perfect situation, pressuring up above or below the element does provide sufficient information as to the condition of the element, because of other perhaps unforeseen leak systems it is not always possible to reliably verify positive inflation of the element. For example, the element being considered may well have been completely positively inflated and may have provided sufficient contact with the well bore wall to function well for its intended purpose, however, if a reservoir is naturally fractured pressuring up above or below the element would likely yield a leak situation which may indicate to the surface and the drill operator that the inflatable element had not completely sealed. Moreover, there may be simply leak ways in the wellbore itself thus providing erroneous information to the surface. Leaking tube joints, fractures in the formation and channeling around the casing are all common difficulties in employing pressure above or below an element to verify seal integrity. There are also some cases in which it is impossible due to other factors to pressure the environment either above or below the seal. In such cases, positive element inflation confidence may not be due to much more than happenstance.